Telephone system



May 6, 1930. w. A. RHODES 1, 5 ,2

TELEPHONE SYSTEM Filed July 2. 192-1 2 Sheets-Sheet 1 /N VE/VTOR VWILL/AM A. fifioaas Wt Arm/awn May 6, 1930.

W. A. RHODES TELEPHONE SYSTEM Filed July 2, 1927 2 Sheets-Sheet 2 /,vVagina; WILL/AM 4. fifiooes Arronmar Patented M y 6, 9

- UNITE, STATES im A.

par-m m V nnonns, on NEW YORK," 1v. Y., gamma-Tommie TELEPHONE ANDTELEGRAPH corfrANY, A oonrona'rroir or NE YORK TELErHoNn SYSTEMApplication. filed July 2, 1927.: j Seria1,'1 To. '203,051.

This invention relatesto telephone systems and has for its object 'theprovision of improved signaling means for suchsystemsg More.specificallythe invention provides" 5 means for causingtheintermlttentoperation of a signal whether said signal is operated or non-operated atthe tlme. 1 Thls 1s accomplished by the insertion of a differentialrelay between the signal and the'interruptingde- Io vice, which tests toascertain whether or not-- the signal is operated. ,If the signal is notoperated, this relay completes a circuit for intermittentl T operatingthe signal and if the si nal is operated, it completes a circuit edsteadily over the called subscriber sjack as adisconnect signal wh nthetrunk is released. In order to. flash thejlamp of. the

30 trunk when reseized before the plug is removed from the 1ack, 1t1snecessaryto internnttent-ly extinguish .the j'disconnect lamp.

This is. brought about by theinclusionof a differential relay intheflashing circuit for the lamp. when the flashing circuit is closed dueto the seizure or reseizure of the trunk, it tests the 7 condition ofthe lamp and'appliesthe proper condition for flashing it. v, This relayalso prevents the application of ringing current to the trunk until theplughas'been removed from the jack and inserted in the proper jack. Apolarized relay controlled by the discharge, through an induct-ion coilwhen a particular circuit-is closed, serves to operate a peg countmeter. 1 ,1 I

The invention willbe more'clearly understoodfrom a'consideration of thefollowing detailed description in connection with the attached dra g ain'which: I

for intermittently extinguishing the signal.

Such trunks may be reseized'atthe,

This relay is so arrangedthat Figure shows a-trunk circuit for a callannouncer; and V I Flg, 2 shows an operators equlpment comuse with inonto -a pluralityof such trunks;

"One form of callannouncer system is disclosed in U. S. Patent 1277,140, granted to A E. Lundell, September3, 1918, and a generalreference-is made thereto although the details thereof are not in allcases applicable i to the present disclosure. A VVhen the subscriber atsubstation 100 initiates acall, his line is extended by means oflinefinder101'to district selector 102 and to a register sender 103. Thesubscriber then dials the-number of the Wanted subscriber, sett ng upxareg stratlon 0n the sender 103 which controls the operatlon of thedistrict selector 102 in selecting an idle trunk to the ofiicev at whichthe-subscriber located. Assuming thatthe called subscriber is-locat'ed-11) an oli ice equlpped vto receive'the called-linenumber by means'of acallan- .nouncer; aclass reglstrat on Wlll .be set :up

in the'sende'r which WlllZCEILlSQ the association ofcall aiinouncer121with the sender 103. When idle trunk has been selected, the sender Willconnecta relay across the trunk conductors in the well known manner,

completing" a circuit from. battery through thelowerlwinding of relay104-, lower; back contact of relay 105, lower left Winding of repeating,coil 10.6, and thence through dis trict selector'l02 and the relay ofthe sender back to the upper left winding of coil 106, upper backcontact of relay 105, upper wind-' ingof'rejlay 104. to ground. Relay 101 operates closing a circuitfrom battery through the left winding ofrelay 107 back contact of relay 108,'to gro undatthe front contact ofrelay-104. 7 V y f in op'eratingcloses a circuit Relay 107 from groundthrough lamp 117 left front Contact of relay .107, conductor 118,primary winding 0oi1 225 tobattery. 'The rush of current produced by theestablishment of this'circuit induces a current inthe secondary windingofthe coil 225 operating polarized.

relay 22 6 in the'direction to close its contact to operate relay 227and meter228. Relay arc-is polarized so as'to prevent its operation onthe opening of the circuit of lamp 117 at-which time the induced currentis in the opposite direction. Relay 227 is slow to re. lease so thatpossible momentary operations of relay 226 will not reoperate the meter.

Lamp117 is common to a'plurality of trunks and indicates that one 'ofthe" group of trunks has been selected atthedistant end. Relay107also'closes a circuitfrom ground over its outer right contact, Windingof relay 109 to'battery. Relay 109 in operating closes a circuitfrom-battery through the, winding of relay 110, right front contact ofrelay 109, right normal contact of relay11-1,'which is individual to thenext trunk of the group,con-

ductor 112, winding of relay 200 to' ground at the back contact of relay.201. .Rel'ays 110 and 109eXt-end "tip and ring conductors of they trunkto the common position equipment,

shown in'Fig. 2, as well as certain control conductors.

' The equipment shown in- Fig.2 is common I to all thetrunksappearing'at that particular position and is available only if theoperator is at the position. When the operator associates her trunk withthe position by means of a jack (not shown) relay 202 operates in serieswith the operators transmitter and repeating coil, in turn operatingrelays 203 and 204 from ground overjtlie positionsplitQ ting circuitwhich.has been omitted from the disclosure. 1 I r lVith relays 203and204 operated, the operation ofrelays 109 110 completes a circuit frombattery throughthe lower right winding of repeating coil" 106,supervisory relay 114, outer left front contact .of relay 110, conductor1.15, left, front'contact relay 203, winding of'relay 205 to ground.Relay 205' operates but due to the high resistance of that relay, relay114 cannot operate. Relay 205 closes a circuit from ground over its.front contact,ba'ck contact of relay 206, winding of relay 207-tobattery 7 Relay 207 closes an operating circuit for relay 108 and ahol'ding'circuitfor relay 107 which may be traced from battery throughthe right winding of relay 108, right Winding of relay 107, inner leftfrontcontact of relays 109 and 110, conductor 113, left front contact ofrelay 204 toground at the left front contact of relay 207; Rela'y 108operates in this circuit and locks throughits left winding to ground atthe front c'ontactof relay 104,

measured interval elapses between the'opera- 'tioniof relay 209 andthe'operatio n of relay 211. lVhen' relay 211 operates it connects bat-V tery over its left front contact to resistance o v 208 thus shunting"and releasing relay 209 and in turn relays 210 and 211. .Relay 211 inoperating also closes a circuit from ground at'it's right front contactthrough the winding of relay 212 to battery.- Relay 212 at eachsistance213 to conductor 214 and ground through resistance2151toconductor 216.1 Re

operation connects battery through the relays 209 to 212 form aninterrupting mechanism whereby battery and groundareintermittentlyconnected to conductors 214 and A t rst is closed frombattery through-the winding operation of relay 212 a circuit.

andnormal contact -'of relay-218, outer left contact of relay 212,to'ground at theinner right front contact of'relay 207.' Relay 218 locksto ground at relay 207 independent of relay-212. Itelay 218 closes anobvious circuit for relay 219 which in turn operates'relay 220 overtheinner right back contact o'f'relay 21. Relay'220 extends its operat-.

' ing circuit to-relay 222 and relay222 closes an'obv-ious circuit forrelay 223. Relay 223 then closes a circuit for relay 221, but relay 221in operating closes a holding circuit for relay 223 overTthe'inner rightalternate contactfjof relay-221' to groundat thefront contactof relay 219. However,the operation of relay 22,1 opens the circuit of relay-220and that inturn opens the circuit of relay 222,

opening theenergizing circuit for relay 223.

Relays 220, 222 and 223 are 'slowto operate in order tointroduce'ameasured interval betwee'n the operation of the various relays.

The purpose ofthis chain of relays is to transmit a pair. of tones tothedistant end of the trunk when; the trunk is seized by an operator.Nhenf'thje trunk is seized by a sender, they serve to prepare the senderfor-transmitting through the lowerri'ght Winding of repeating coil 106,winding of relay 114, outer left front 7 contact of relay 110, conductor115, left front 7 contact of relay-203, left back contact of relay 221,left front contact of relay 219, secondary winding oftone coil224, thenext to the inner right contact of relay 219, outer right back contactof relay 221, right front contact of relay 203, conductor 1-16,middle-left contact of relay 110, outer left contact of relay 109,

upper right Winding of repeating coil 106 to ground; Relay 114noWoperates closing a a called line number. When relay 219 opcrates itcompletes 'a' circuit from battery circuit from battery through the"winding 7 of relay 105," front contact of relay 114, to ground at theinner right contact of relay 108. The operation of relay reverses theconnection of relay 104 to the tip and ring conductors of the trunk andby reversing the polarity of the current flowing thereover preparesthesender to make call announcement. When relay 221 operates, it discon,

nects coil'224 from the' windingof relay 114 and relay 114' releasesinturnreleasing relay 105 and restoring the'polarity over the trunkcircuit.

Relay 219 in operating also closes a circuit from batterythrough lamp119, outer right frontcontact of relay 110, conductor 120, winding ofrelay229, neXt'to the outerj right contact of relay 219, to the outerright,armature of relay 207, whence the circuit extends through the leftwinding andleft back con tact of relay 230 to intermittent ground overconductor 216,- Lamp 119is caused to'flash in this circuit. It will benoted that a second icircuit exists from battery throughthe rightWinding of relay 230, contacts of relay 207, left 'windin' 'and leftback, contact of relay 230 to intermittent ground over conductor 216.However, relay 230 is; so wound that the combined eil'eot of the two 1circuits throughfthe left winding of 'relay230ju'st neutralizes theefiect of the circuitthrough the right winding thereof and relay 230remains deenergized. the above traced circuit closing anobviouscircuitforlamp'231 which is individual to the position. Relay 229-beingslow to release holds lamp 231 lighted steadily.

TV hen relay 221' operates disconnecting coil 224 irom'the winding ofrelay 114,'it'c0nnects ber of the wanted subscriber, she operates re-vlease key 232,'which completes a circuit from ground over key 232, outerright frontcontact of relay 204, left back contact of relay 1 230,winding of relay 206 to battery. Relay '206 locks over its front contactto ground at the front contact or" relay 221 or the'front contactotinterrupter relay-212, thus insuring that relay 206 will be the lastrelay to release. the circuitbf relay 207 in turn opening the energizingcircuit of relay 108 and the holding circuit of relay 107. Relay 207also opens I the flashing circuit for lamp 119, releasing relay229 andopening the circuit-ofrelay 230. It also opens the holding'clrcuit ofrelay 218 which causes the release of'rela ys 219,

223, and 221 insuccession. As soona'srelay 212opens its contact, relay206 releases and theposition circuit .is restored: to normal. T herelease of relay causes the release of relaylO'l' and extinguisheslamp117. lVith relay 107 released,relays 109 and 11 0 release and theposition circuit may be usedfwith another trunk.- I r Theoperator thentests the called subscribers line in the usual manner and finding it.idle inserts plug 122 in ack 123, whereupon Relay 229 operates in At itsleft contactrelay 206 opens" a circuit is-closed froin groundthroughtheI winding of the subscribers cut-ofirelay l24, sleeve of jack 123 and;plug122, lower wind tery. Relays-124 andg125foperate this circuit, relay125%01051118 a circuit 'inparalingiof relay 125 throughflanip 11 9 to-batlel with lamp 119 which maybe traced from ground,"- through the"winding of relay: 124,

sleeve of jack? 123 and plug .122",- low'e'r windingot relay 125,;leftfront contact of "relay 108, rightb'ack contact ofrelaylO'l, inner upperfront contact of relay 125,back'con-' tacts of relaysl127 and 128mara-unmet, i

the winding'of relay-128, winding ofrelay 129 to battery.- Relay-129operatesclosinga'circuit, from ground over its upper front contact 0 andtheouter upper front contact oifi relay 125, to the ti pfof plug 122 andthe tip conductor of the subscribers line, back; over thering'conductor, over the ring of jack 123 and plug 122, lower frontcontact of relay" 129,. winding of relay 127 to source of1'inging.cur;-.

rent 126. Relay 127 is insensitive to ringing current but as soon asthecalled subscriber a answers closing a directcurrent path,'relay 1'27operates, openmgtheshunt around relay 128, which in turn operates andlockstob attery at its front contact. This battery shunts relay 129causing that relay towreleaseand extend the subscribers line through tothe right windings of repeating coil 106.1This completes a circuit for"relay 114 which again operates relay 105 and reverses ther'current overthe trunk conductors which reversal is now effective for anydGSlI'GtlSllPBIVISOIY purpose; The circuitiremainsxin; this conditionuntil conversation is ended atwhichtimethe Y restoration ofthe calledsubscribers receiver releases relay 114, releasing relay105. andrestoring the connection of relay. 104.." When 124 as adisconnectsignal.

Should the trunk be i-eseize'd at thedistant end ,bet'orelthe'"operatorremoves plug from jack 123, the operationsf'willproceed I as abovedescribed until'the circuitiis established tothe outer right armature ofrelay 1207, through lamp 119. Due tothepresence of plug. 122in jackleaiground willbe con;

nected to the armature-of relay207 instead of battery as in the previouscase; This re,- sults in the establishmentofa circuit through the rightwinding of relay 230, but since ground is connectedto'theleft-windingofrelay 230 over the back contact of that relay thecalling subscriberrestores his receiver, re- I lay1O4 releases and relay108 also relea'sesin .turn releasing relay 128. Lamp 119 .now lightssteadily in series with. relays 125 and as well' as through the windingof relay 124. a i A the current flow in this windingwill be great- 2 1yreduced and'the'relay will operate due to:

the unbalanced condition. With relay230 operated-the circuitthrough-theleft winding r of that relay is'extended over its left front contacttointermittent 'batteryfover' conductor I 214. This circuita-ids inoperation of relay 230-each time it, is closed, so'that relay 230remains operated as long as ground is connected: to lamp 1191-ove1g theplug 122.

'- operator,

Lampr1l9 istherefore intermittently shunted and thusflashes toattractthe attention otthe .Should'thebperator disconnect I her positionequipment from tihe trunk with OlltafiISt removing the plug fromtheljack, the operation of key 232 is inefiective, since thecircuit of relay206 is open. atirthe contact of relay 230. The removal of plug 122 fromthe jack removes ground fromthearmature minals to 'batte'ryof a givenpolarity, and I of relay 207and from relay-2 30 .whiclnreleases tocontinue flashing lamp 119 by means of intermittent ground onconductor216; The release of relayv 230 renders release; key 232effective: and the. connection may be com-. pleted in the usuaImann'er.In case the-circuit of lamp 119, should-be gnounded .falsely,

' an emergencykey; 23 l is provided'which will operate relay 2O6directly, even though relay 230may-be operated. v [,What isclaimed is: 1I

1-.' In a signaling system, an electrically operable signal connectedatone of its termeans connectedto another terminal of said signal tocause a characteristicoperation of said signal by associating-Withsaidother terminal battery of the same or opposite polarity. V w Z 2." In asignaling system, an electrically operable signal'connected'at one ofits terminals to battery of a givenpolarity, and means conneeted toanother terminal'of said signal to cause said signal-to beintermittently operatedunde'r varying conditions, by associating withsaid other terminal interrupted battery of the same-or oppositepolarity. v

Ina: signaling system, anelectrically operable signal connected: at-oneof its terminals to batteryofa given polarity, means connected to asecond terminalof said signal to vary the conditions under which saidsignal is operated, and va differentially. connected relay responsive tothe condition connectedto said second terminal for-controlling theassociation of'battery of thef-sainepor opposite polarity with saidsecond terminal to cause the operationof said signal; I a V, v c

4. In a signaling system, anieleotricallyoperable signal connected atone of its tennis nalsto battery of a given polarity-and voltage, andmeans connected to another termi-,

nal of said signal to causesaidsignal to be intermittently operated(underwarying con:

- ditions by associating with said other terminal-interrupted battery.of the same or op:

' pos-ite polarity and the same voltage.

5. Ina signaling system, ,an'lelectrically operable signalconnected'ilatoneqof, its ter- -minals to battery of";a ,.given polarityand voltage, means connected to. a,,second,= termi-v interrupters.

nal of said signal to vary thecond-itions under v which said signal. isoperated, and adifiierena tiall-y' connected relay, responsive to'thecondition connected to said second terminal, for

controlling the association of battery of the same or opposite polarityand the samevolt- 7 age with said second terminalto cause the op-"eration of said signal. I I p 6. In asignaling system, an electricallyop- 'erablesignal, means to cause the steady operation of said-signal,and means to cause the intermittent operation of said signal, saidlast'means being efiective alone or in combination with said firstmentioned means" j "7. In a telephone system, a plug ended trunk, ajack, a signal'associated with said trunk, meansefiective when the plugof the trunk is in said jack to causethe steady operation ,ofsaid'signal, and means for causing the intermittent operation of saidsignal com'prisinga plurality ofinterrupters, and

means'fortesting whether or not said signal is operated fordiscriminating between said 8.-In a telephone; system, a plug endedtrunk, a jack, a signal associated with said trunk; connected atone ofits terminals to battery. of'a given polarity, means effectivediscriminate between. said interruptersa 9-..Ina telephone system, aplug ended trunk, a jack, a signal associated withsaid trunk connectedat one of its terminals to battery of a given polarity, means effectivewhen theplug of said trunk is inserted in said jack to cause the steadyoperation of said no signal, and means forgcausing the intermits tentoperat1on"of sa1'd lslgnal comprising an interrupterv I connected to V,the same battery polarity as is connected to said signal, a sec-. ondinterrupterrconnected to battery of the opposite polarity, and adifierentially c0'n-. nected relay for testing whether or not saidsignal} is operated to discriminateibetween said interru'pters.

In a telephone system, plug ended trunks,. acks, operators equipmentcommon to said trunks,asignal associated with each, of said trunks,means effective when a plug of one of said-trunks is in one of saidjacks to cause. the steady operation of the correspending signal, meansin said common apparatus to cause; the intermittent operation of saidslgnal comprisinga plurality of inter- I rupters, means'for testingwhether or not said signal is operatedfor discriminating be tween saidinterrupters, and means for releasing said common apparatus from saidtrunln'saidmeans beingv under the control of said testing means. I v

11. In a signaling system, an electrically operable signal connectedatone of its termi nals to battery of a given polarity andivoltage, meansconnected to a second termmalof said signal to varythe conditions underwhich said signal is operated, and means for causing the intermittentoperation of said signal comprising an interrupter connected to the samebattery polarity as is connected to said signal, a secondinterrupterconnected to battery of the opposite polarity andaudiiierentiallywound'relay for-testing whether or not said signal isoperated, said relay being normally in series with-said signal and saidsecondinterrupter overits back contact and when operated in series Withsaid slgnal and said first lnterrupter over its front contact.

12. In a signaling system, an electrically operable signal connectedatone of its terminals to battery of a given polarity and voltage, meansfor connecting the other terminal terminal of said signal, a secondinterrupter connected to battery of the oppositepolarity andadifierentially wound relay for testing Whether or not said signal isoperated, said relay being normally in series With said sig- 7 nal andsaid second interrupter over its back contact and inoperative 1fsaldsignal 1s not at the time. operated andoperative if said signal isoperated to connect itself in series with said signal and said firstinterrupter over its front contact.

In testimony whereof, I havesigned my: a name to. this specificationthis 'lst'day of July, 1927. V

, WILLIAM A. RHODES.

